1. Field of the Invention
The present invention relates to guidewires for traversing vessels of vascular systems, and more specifically to guidewires having a radiopaque distal end that bends yet reliably transmits steering torques.
2. Description of the Prior Art
Percutaneous angioplasty is a therapeutic medical procedure that can increase blood flow through a blood vessel. It can sometimes be used as an alternative to coronary by-pass surgery. An elongated guidewire is fed into the patient's vascular system through an incision in the groin. The guidewire tip is guided into position in a coronary artery. A catheter having a deflated balloon near its distal end is fed along the guidewire through the patient's cardiovascular system to a narrowed section of the coronary artery where the angioplasty is to be performed. When properly positioned, the balloon is inflated to compress deposits that have accumulated along the inner wall of the coronary artery to widen the artery lumen and increase blood flow.
The guidewire is steered through the cardiovascular system and its progress is viewed on an x-ray imaging screen. The guidewire tip is advanced through the narrowed coronary artery section in order to position the balloon in the narrowed section. The guidewire tip must be steered through tortuous vessels and/or through junctures of vessels that require tight turns. The tip is bent to facilitate steering the guidewire around tight turns. The proximal guidewire end is twisted about its axis to transmit torque through the guidewire for steering its tip.